应用X射线衍射仪、扫描电镜和能谱分析仪 ,研究了Al Si Cu钎料中Cu在真空钎焊接头中的腐蚀与扩散行为 .研究结果表明 ,真空钎焊后的接头仍然存在腐蚀问题 ,如点蚀和晶间腐蚀等 ,并且随着w(Cu)的增加腐蚀加重 .Cu在钎焊接头中以晶界扩散为主 ,且晶界扩散比晶内扩散快 . The corrosion and diffusion behavior of Cu in vacuum brazed joints of Al Si Cu brazing filler metal were investigated by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy.The results show that there are still corrosion problems in joints after vacuum brazing, Such as pitting corrosion and intergranular corrosion, etc., and the corrosion increases with the increase of w (Cu) .Cu is dominated by grain boundary diffusion in the brazed joints, and the grain boundary diffusion is faster than intragranular diffusion.